Idle RPMs between 500-750 - Page 2 - MustangForums.com

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Idle RPMs between 500-750

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Old 12-22-2010, 07:24 PM
  #11  
kugzgt
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i hate how expensive our iacs are
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Old 12-22-2010, 07:34 PM
  #12  
sportsguy0502
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everything on our cars are expensive compared to my friends hondas/acuras. the iac are only like 60 bucks
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Old 12-23-2010, 05:43 AM
  #13  
uberstang1
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Originally Posted by uberstang1 View Post
What do you mean by half was still left on the spark plug? If you mean half of the spring contact from the old wire is still on the plug and you just rammed a new wire over it or just put the rest of the broken wire back on I would say thats more than likley the problem. If the plugs were getting real bad some of the older plugs may cause you to have a few sloppy cylinders. You really should change the rest of the plugs IMO and replace the broken wire or maybe all of the wires. Also some of the new plugs may be gapped different than the older plugs still in the engine. If you are new to working on stuff and have little expereince I would HIGHLY recommend using a torque wrench to torque the spark plugs to spec because these heads have a reputation for blowing out plugs.
I stay by my original post, before you start buying IACs or throwing other stuff at it, first thing is first, you have a couple old plugs in there mixed with a couple new plugs, old wires and a broken wire. If i were you before I did anything I would get all the new plugs in and either all new wires or atleast replace the broken one. If the plugs were old enough and were starting to loose efficency, now you have a couple cylinders running slopping and a complete cylinders that are running fresh, as in you have a good combustion in the cylinders with the new plugs compared to a poor combustion in the cylinders with the old plugs which may lead to the syptoms you are describing and feel like a miss or rough idling.

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Old 12-23-2010, 09:03 AM
  #14  
98redstang
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+1 op i would get all new fresh stuff in there first. And i wouldnt say you need a new iac. A lot of the time they just get a lot of crap in them and just need to be cleaned out. Im betting on this being your problem.
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Old 12-23-2010, 10:05 AM
  #15  
sportsguy0502
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Hey guys, thanks for all the replies, im changing the rest of the plugs today, and dont plan on buying a new IAC, just cleaning. When i pulled the old plugs out, seems like the plug was kinda corroded. Does that mean the car is running lean?
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Old 12-23-2010, 11:18 AM
  #16  
98redstang
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if the plug is white its running lean. If its dark and smells like gas its rich and if its tanish its burning good. There are other ways to look like at certain parts of the plug but thats the basics of it. Either way if you haven't changed them in a while it needs to be done. But as i said before the way you explain the rpms dropping and going up is very commonly caused by the iac.
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Old 12-23-2010, 03:18 PM
  #17  
sportsguy0502
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i changed them all, and the idle is not how it was before, but closer. In the process of changing the plugs, i broke another boot of the wire, so i am changing the wires next, and hope that helps. Do you guys have any favorite wires that you like?
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Old 12-24-2010, 06:10 AM
  #18  
uberstang1
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Ford racing wires would be sufficent
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Old 12-25-2010, 08:44 AM
  #19  
98redstang
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did you clean the iac yet?
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Old 12-26-2010, 03:18 PM
  #20  
sportsguy0502
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i have not, and prob wont be able to since its now snowing where i am, and have to garage, but i ordered ford racing wires, so when i get them, i will clean the iac.
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